Structure of Kaluza-Klein Graviton Scattering Amplitudes from Gravitational Equivalence Theorem and Double-Copy

We study the structure of scattering amplitudes of the Kaluza-Klein (KK) gravitons and of the gravitational KK Goldstone bosons in the compactified 5d General Relativity (GR). We analyze the geometric Higgs mechanism for mass-generation of KK gravitons under compactification with a general $R_\xi$ gauge-fixing, which is free from vDVZ discontinuity. Then, we formulate the Gravitational Equivalence Theorem (GET) to connect the longitudinal KK graviton amplitudes to the KK Goldstone amplitudes, which is a manifestation of the geometric Higgs mechanism at $S$-matrix level. We directly compute the tree-level KK Goldstone amplitudes which equal the longitudinal KK graviton amplitudes in the high energy limit. We further use the double-copy method with color-kinematics duality to reconstruct the KK longitudinal graviton (Goldstone) amplitudes from the KK longitudinal gauge boson (Goldstone) amplitudes in the compactified 5d Yang-Mills (YM) theory, under the high energy expansion. From these, we reconstruct the GET of the KK longitudinal graviton (Goldstone) amplitudes in the 5d GR from the KK longitudinal gauge boson (Goldstone) amplitudes in the 5d YM theory. Using either the GET or the double-copy reconstruction, we provide a theoretical mechanism showing that the sum of all the energy-power terms [up to $O(E^{10})$] in the high-energy amplitudes of four longitudinal KK gravitons must cancel down to $O(E^2)$ as enforced by matching the energy-power dependence of the corresponding KK Goldstone amplitudes or by matching that of the double-copy amplitudes from the KK YM theory. With the double-copy approach, we establish a new correspondence between the two energy-cancellations: $E^4 \to E^0$ in the 5d KK YM theory and $E^{10} \to E^2$ in the 5d KK GR theory. We further analyze the structure of the residual terms in the GET and uncover a new energy-cancellation mechanism therein.Comment: 80 pages. Refined version with new discussions added on N-point KK amplitudes. Conclusions unchanged. Typos corrected and references adde

4-Meth­oxy-3-(trifluoro­meth­yl)aniline

In title compound, C8H8F3NO, the meth­oxy group is inclined at 8.7 (4)° to the benzene ring plane. The crystal structure is stabilized by inter­molecular N—H⋯F, N—H⋯N and C—H⋯F hydrogen-bonding inter­actions

A double neutron star merger origin for the cosmological relativistic fading source PTF11agg?

The Palomar Transient Factory (PTF) team recently reported the discovery of a rapidly fading optical transient source, PTF11agg. A long-lived scintillating radio counterpart was identified, but the search for a high energy counterpart showed negative results. The PTF team speculated that PTF11agg may represent a new class of relativistic outbursts. Here we suggest that a neutron star (NS)-NS merger system with a supra-massive magnetar central engine could be a possible source to power such a transient, if our line of sight is not on the jet axis direction of the system. These systems are also top candidates for gravitational wave sources to be detected in the advanced LIGO/Virgo era. We find that the PTF11agg data could be explained well with such a model, suggesting that at least some gravitational wave bursts due to NS-NS mergers may be associated with such a bright electromagnetic counterpart without a \gamma-ray trigger.Comment: Accepted for publication in ApJ Letter

LHC Higgs Signatures from Topflavor Seesaw Mechanism

We study LHC Higgs signatures from topflavor seesaw realization of electroweak symmetry breaking with a minimal gauge extension SU(2) x SU(2) x U(1). This elegant renormalizable construction singles out top quark sector (instead of all other light fermions) to join the new SU(2) gauge force. It predicts extra vector-like spectator quarks (T, B), new gauge bosons (W', Z'), and a pair of neutral Higgs bosons (h, H). We demonstrate that for the lighter Higgs boson h of mass 125GeV, this model predicts modified Higgs signal rates in h --> \gamma\gamma, WW*, ZZ* channels via gluon fusions, in h --> tau tau mode via vector boson fusions, and in h --> bb mode via gauge boson associate productions. We perform a global fit for our theory by including both direct search data (LHC and Tevatron) and indirect precision constraints. We further analyze the LHC discovery potential for detecting the heavier Higgs state H.Comment: PLB published version. Only minor refinements, typos corrected, references adde

Massive Color-Kinematics Duality and Double-Copy for Kaluza-Klein Scattering Amplitudes

We study the scattering amplitudes of massive Kaluza-Klein (KK) states under toroidal compactification. We present a shifting method to quantitatively derive the scattering amplitudes of massive KK gauge bosons and KK gravitons from the corresponding massless amplitudes in the noncompactified higher dimensional theories. With these we construct the massive KK scattering amplitudes by extending the double-copy relations of massless scattering amplitudes within the field theory framework, including both the BCJ and CHY methods, and build up their connections to the massive KK KLT relations. We present the massive BCJ-type double-copy construction of the $N$-point KK gauge boson/graviton scattering amplitudes, and as the applications we derive explicitly the four-point KK scattering amplitudes as well as the five-point KK scattering amplitudes. We further study the nonrelativistic limit of these massive scattering amplitudes with the heavy external KK states and discuss the impact of the compactified extra dimensions on the low energy gravitational potential. Finally, we analyze the four-point and $N$-point mass spectral conditions and newly propose a novel group theory approach to prove that only the KK theories under toroidal compactification can satisfy these conditions for directly realizing massive double-copy in the field theory framework.Comment: 73 pages, JHEP final version. Only minor refinements, references adde

Plasma gelsolin levels and outcomes after aneurysmal subarachnoid hemorrhage

INTRODUCTION: Lower gelsolin levels have been associated with the severity and poor outcome of critical illness. Nevertheless, their link with clinical outcomes of aneurysmal subarachnoid hemorrhage is unknown. Therefore, we aimed to investigate the relationship between plasma gelsolin levels and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage. METHODS: A total of 262 consecutive patients and 150 healthy subjects were included. Plasma gelsolin levels were measured by enzyme-linked immunosorbent assay. Mortality and poor long-term outcome (Glasgow Outcome Scale score of 1-3) at 6 months were recorded. RESULTS: Plasma gelsolin levels on admission were substantially lower in patients than in healthy controls (66.9 (26.4) mg/L vs. 126.4 (35.4) mg/L, P < 0.001), and negatively associated with World Federation of Neurological Surgeons score (r = -0.554, P < 0.001) and Fisher score (r = -0.538, P < 0.001), and identified as an independent predictor of poor functional outcome (odds ratio, 0.957; 95% confidence interval (CI), 0.933-0.983; P = 0.001) and death (odds ratio, 0.953; 95% CI, 0.917-0.990; P = 0.003) after 6 months. The areas under the ROC curve of gelsolin for functional outcome and mortality were similar to those of World Federation of Neurological Surgeons score and Fisher score (all P > 0.05). Gelsolin improved the predictive values of World Federation of Neurological Surgeons score and Fisher score for functional outcome (both P < 0.05), but not for mortality (both P > 0.05). CONCLUSIONS: Gelsolin levels are a useful, complementary tool to predict functional outcome and mortality 6 months after aneurysmal subarachnoid hemorrhage